Apparatus for making nitrogen oxids from the air.



No'.. 88%920. PATENTED APR. 14, 1908.

- A. GRAUK: F. RUSS.

' APPARATUS FOR MAKING NITROGEN OXIDS FROM THE AIR.

APPLICATION FILED OGT.8, 1907.

INVENTURS 4:43:45? (731w, Fran 1 3m:

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ATTORNEY AUGUST GRAU AND FRANZ RUSS; OF VIENNA, AUSTRIA-HUNGARY.

No. esaseo.

Specification of Letters Patent. I

arraaerus F033. Mannie NITEGGEN omns racer THE are.

Patented April 14, 190$.

- Application and October 8, 190-1. stun-no. seaesr.

- Tacit whom it may concern:

Be it known that we, AUGUST GRAU, professor' of electrical arts, and FRANZ Russ, doctor of technical sciences, subjects of the Emperor of Austria-Hungary, residing at Vienna, Austria Hungary, have invented certain new and useful Improvements in A paratus for Making Nitrogen Oxids from t e Air, of which the following is a specification.

Our invention relates to apparatus for the production of oxids of nitrogen by ex using a mixture of nitrogen and oxygen to t e action of an electric arc.

It is well known that the higher the temperature to which the. mixture of nitrogen and oxygen, hereinafter referred to as air, is exposed the greater is the percentage of ox: ids of nitro en obtained, and also that the re action at the very high temperatures of the electric arc is ractically instantaneous. When the gases, owever, are cooled down slowly from the highest temperature, dissociation of the oXids of nitrogen back again into oxy en and nitrogen takes place and many methods have been suggested for cooling down the hot reaction gases as rapidly as v ossible in order to prevent such dissociation rom taking place to any great extent. Now since the inner part of an electric arc is hotter than the outer Zones, the concentration of the oxids of nitrogen is greater in the inner than in the outer zones.

Our improved apparatus is so constructed that we draw the gases from the center or in- .ner zone of the electric flame to the exclusion or substantially to the exclusion of the outer zones or outside of the flame, and we do not permit the gases to become partially dissociated by passing through the outer zones, and in this way our app: :ztus differs from any hitherto described. In order to take the ases substantially from the central zone oi the flan 2 ve use a tube of substantially the same diameter as the inner zone of the flame projecting into the said inner zone of the flame and withdraw the gases through this tube. We also cool this tube, for instance by means of a wateror ainjacket, on the one hand to prevent the tube from melting and also re idly to cool the gases being withdrawn own to a temperature under 1500 C. since the dissociation below this temperature is only very small. If desired, two or more such tubes may be introduced into the flame, or one electrode itself may be hollow and act as the tube through which the gases are withdrawn. The tube or the hollow electrode through which the gases are withdrawn is preierabl made of iron and as aforesaid it is protects from melting or oxidizing too rapidly by cooling by means of an air or water jacket. It is of course preferable that the electric flame should be as steady as ossible, otherwise gases other than those om the central zone will be drawn through the tube and for this pur ose it is preferred to make use of a perpen icular flame surrounded by a tube. If desired, this surroundihg tube can be closed with the exception of at and outlet pipes so that other mixtures of nitrogen and oxygen, for instance air mixed with oxygen, can be treated in the flame.

'l e drawings accompanying this specification will help to illustrate further our new apparatus, but we do not limit our invention to the apparatus shown therein.

Figures 1, 2, 3 and 4 are all diagrammatic sections of'ap aratus showing Where the flame is formed an how the gases are withdrawn from the central Zone.

In Fig. 1, a, b are electrodes, 0 is the inner and d are the outer zones of the electric flame and e is the narrow tube through which the gases are withdrawn.

In Fig. 2, a, b are electrodes and the flame is shown surrounded by a tube f, the air, or other mixture of oxygen and nitrogen, enters through it and the gases are withdrawn through two narrow tubes 6, e, assing through openings g, g, in the side of t e tube f and projecting into the central zone of the flame.

Fig. 3 represents an apparatus in which the electrode a is. hollow and serves as the narrow tube through which the gases are withdrawn from the central zone, I) is the other electrode, is the tube surrounding the flame, and h is the opening through which the air enters the tube Fig. 4 represents a modification of the apparatus shown in Fig. 3 in which the tube f in which the flame is formed is surrounded by a wider tube t. The air to be treated is made to pass between the tubes 11 and f and then to enter the tube f, thus cooling the tube 14 and at the same time warming the air whic is to be treated in the flame. In this case also the gases are drawn from the central zone of the flame through the electrode a.

In this application we make no claim to the process described herein, since we desire to claim such process in another application of like date with the present application Serial No. 396,436.

What we claim is:

1. In ap )aratus for the manufacture of nitrogen oxiiis from the air in combination with an electric furnace for producing the arc flame, an exit tube for the treated gases of substantially the same diameter as the inner zone of the flame projecting into the said inner zone of the flame substantially as described.

2. In apparatus for the manufacture of nitrogen oxids from the air in combination with the rest of an electric furnace for producing the arc flame a tubular electrode and exit tube for the treated gases of substantially the same diameter the inner zone of the are flame substantially as described. 7 x

3. in apoaratus for the manufacture of nitrogen oxids from the air in combination with an electric furnace for producing the arc [lame an exit tube for the treated gases of substantially the same diameter as the inner zone of the flame and projecting into the said inner zone of the flame and means for cooling the said exit tube substantially as described.

4. In apoaratus for the manufacture of nitrogen oxide from the air in combination with the rest of an electric furnace for producing the are flame a tubular electrode and exit tube for the treated gases of substantially the same diameter as the inner zone of the flame and means for cooling the said exit tube electrode substantially described.

In testimony whereof we have hereunto set our hand in presence of two subscribing witnesses.

AUGUST GRAU. FRANZ RUSS.

l Vitnesses:

UsTAv Pnrnrrrrrscn, *7 ltoBER'r W HEINGARTNER. 

